drivers/i2c/busses/i2c-thunderx-pcidrv.c

   1 /*
   2  * Cavium ThunderX i2c driver.
   3  *
   4  * Copyright (C) 2015,2016 Cavium Inc.
   5  * Authors: Fred Martin <fmartin@caviumnetworks.com>
   6  *          Jan Glauber <jglauber@cavium.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2. This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/clk.h>
  15 #include <linux/delay.h>
  16 #include <linux/i2c.h>
  17 #include <linux/i2c-smbus.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/pci.h>
  23
  24 #include "i2c-octeon-core.h"
  25
  26 #define DRV_NAME "i2c-thunderx"
  27
  28 #define PCI_DEVICE_ID_THUNDER_TWSI      0xa012
  29
  30 #define SYS_FREQ_DEFAULT                700000000
  31
  32 #define TWSI_INT_ENA_W1C                0x1028
  33 #define TWSI_INT_ENA_W1S                0x1030
  34
  35 /*
  36  * Enable the CORE interrupt.
  37  * The interrupt will be asserted when there is non-STAT_IDLE state in the
  38  * SW_TWSI_EOP_TWSI_STAT register.
  39  */
  40 static void thunder_i2c_int_enable(struct octeon_i2c *i2c)
  41 {
  42         octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
  43                                 i2c->twsi_base + TWSI_INT_ENA_W1S);
  44 }
  45
  46 /*
  47  * Disable the CORE interrupt.
  48  */
  49 static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
  50 {
  51         octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
  52                                 i2c->twsi_base + TWSI_INT_ENA_W1C);
  53 }
  54
  55 static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
  56 {
  57         octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
  58                                 i2c->twsi_base + TWSI_INT_ENA_W1S);
  59 }
  60
  61 static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
  62 {
  63         octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
  64                                 i2c->twsi_base + TWSI_INT_ENA_W1C);
  65 }
  66
  67 static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
  68 {
  69         return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
  70                I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
  71 }
  72
  73 static const struct i2c_algorithm thunderx_i2c_algo = {
  74         .master_xfer = octeon_i2c_xfer,
  75         .functionality = thunderx_i2c_functionality,
  76 };
  77
  78 static const struct i2c_adapter thunderx_i2c_ops = {
  79         .owner  = THIS_MODULE,
  80         .name   = "ThunderX adapter",
  81         .algo   = &thunderx_i2c_algo,
  82 };
  83
  84 static void thunder_i2c_clock_enable(struct device *dev, struct octeon_i2c *i2c)
  85 {
  86         int ret;
  87
  88         if (acpi_disabled) {
  89                 /* DT */
  90                 i2c->clk = clk_get(dev, NULL);
  91                 if (IS_ERR(i2c->clk)) {
  92                         i2c->clk = NULL;
  93                         goto skip;
  94                 }
  95
  96                 ret = clk_prepare_enable(i2c->clk);
  97                 if (ret)
  98                         goto skip;
  99                 i2c->sys_freq = clk_get_rate(i2c->clk);
 100         } else {
 101                 /* ACPI */
 102                 device_property_read_u32(dev, "sclk", &i2c->sys_freq);
 103         }
 104
 105 skip:
 106         if (!i2c->sys_freq)
 107                 i2c->sys_freq = SYS_FREQ_DEFAULT;
 108 }
 109
 110 static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
 111 {
 112         if (!clk)
 113                 return;
 114         clk_disable_unprepare(clk);
 115         clk_put(clk);
 116 }
 117
 118 static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
 119                                       struct device_node *node)
 120 {
 121         u32 type;
 122
 123         if (!node)
 124                 return -EINVAL;
 125
 126         i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
 127         if (!i2c->alert_data.irq)
 128                 return -EINVAL;
 129
 130         type = irqd_get_trigger_type(irq_get_irq_data(i2c->alert_data.irq));
 131         i2c->alert_data.alert_edge_triggered =
 132                 (type & IRQ_TYPE_LEVEL_MASK) ? 1 : 0;
 133
 134         i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
 135         if (!i2c->ara)
 136                 return -ENODEV;
 137         return 0;
 138 }
 139
 140 static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c,
 141                                    struct device_node *node)
 142 {
 143         /* TODO: ACPI support */
 144         if (!acpi_disabled)
 145                 return -EOPNOTSUPP;
 146
 147         return thunder_i2c_smbus_setup_of(i2c, node);
 148 }
 149
 150 static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c)
 151 {
 152         if (i2c->ara)
 153                 i2c_unregister_device(i2c->ara);
 154 }
 155
 156 static int thunder_i2c_probe_pci(struct pci_dev *pdev,
 157                                  const struct pci_device_id *ent)
 158 {
 159         struct device *dev = &pdev->dev;
 160         struct octeon_i2c *i2c;
 161         int ret;
 162
 163         i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
 164         if (!i2c)
 165                 return -ENOMEM;
 166
 167         i2c->roff.sw_twsi = 0x1000;
 168         i2c->roff.twsi_int = 0x1010;
 169         i2c->roff.sw_twsi_ext = 0x1018;
 170
 171         i2c->dev = dev;
 172         pci_set_drvdata(pdev, i2c);
 173         ret = pcim_enable_device(pdev);
 174         if (ret)
 175                 return ret;
 176
 177         ret = pci_request_regions(pdev, DRV_NAME);
 178         if (ret)
 179                 return ret;
 180
 181         i2c->twsi_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
 182         if (!i2c->twsi_base)
 183                 return -EINVAL;
 184
 185         thunder_i2c_clock_enable(dev, i2c);
 186         ret = device_property_read_u32(dev, "clock-frequency", &i2c->twsi_freq);
 187         if (ret)
 188                 i2c->twsi_freq = 100000;
 189
 190         init_waitqueue_head(&i2c->queue);
 191
 192         i2c->int_enable = thunder_i2c_int_enable;
 193         i2c->int_disable = thunder_i2c_int_disable;
 194         i2c->hlc_int_enable = thunder_i2c_hlc_int_enable;
 195         i2c->hlc_int_disable = thunder_i2c_hlc_int_disable;
 196
 197         ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
 198         if (ret < 0)
 199                 goto error;
 200
 201         ret = devm_request_irq(dev, pci_irq_vector(pdev, 0), octeon_i2c_isr, 0,
 202                                DRV_NAME, i2c);
 203         if (ret)
 204                 goto error;
 205
 206         ret = octeon_i2c_init_lowlevel(i2c);
 207         if (ret)
 208                 goto error;
 209
 210         octeon_i2c_set_clock(i2c);
 211
 212         i2c->adap = thunderx_i2c_ops;
 213         i2c->adap.retries = 5;
 214         i2c->adap.class = I2C_CLASS_HWMON;
 215         i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
 216         i2c->adap.dev.parent = dev;
 217         i2c->adap.dev.of_node = pdev->dev.of_node;
 218         snprintf(i2c->adap.name, sizeof(i2c->adap.name),
 219                  "Cavium ThunderX i2c adapter at %s", dev_name(dev));
 220         i2c_set_adapdata(&i2c->adap, i2c);
 221
 222         ret = i2c_add_adapter(&i2c->adap);
 223         if (ret)
 224                 goto error;
 225
 226         dev_info(i2c->dev, "Probed. Set system clock to %u\n", i2c->sys_freq);
 227
 228         ret = thunder_i2c_smbus_setup(i2c, pdev->dev.of_node);
 229         if (ret)
 230                 dev_info(dev, "SMBUS alert not active on this bus\n");
 231
 232         return 0;
 233
 234 error:
 235         thunder_i2c_clock_disable(dev, i2c->clk);
 236         return ret;
 237 }
 238
 239 static void thunder_i2c_remove_pci(struct pci_dev *pdev)
 240 {
 241         struct octeon_i2c *i2c = pci_get_drvdata(pdev);
 242
 243         thunder_i2c_smbus_remove(i2c);
 244         thunder_i2c_clock_disable(&pdev->dev, i2c->clk);
 245         i2c_del_adapter(&i2c->adap);
 246 }
 247
 248 static const struct pci_device_id thunder_i2c_pci_id_table[] = {
 249         { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) },
 250         { 0, }
 251 };
 252
 253 MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table);
 254
 255 static struct pci_driver thunder_i2c_pci_driver = {
 256         .name           = DRV_NAME,
 257         .id_table       = thunder_i2c_pci_id_table,
 258         .probe          = thunder_i2c_probe_pci,
 259         .remove         = thunder_i2c_remove_pci,
 260 };
 261
 262 module_pci_driver(thunder_i2c_pci_driver);
 263
 264 MODULE_LICENSE("GPL");
 265 MODULE_AUTHOR("Fred Martin <fmartin@caviumnetworks.com>");
 266 MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");